Yeah, I definitely want to avoid that feeling, of me being the GM I mean. Just remember, I only have one defined plot-point past the start, and it's basically impossible for you to over-write it. So once I get the initial post done, you're pretty much in equal standing to me in terms of author power.

I think I'll jot down some details about my two as well, and make the first post tomorrow most likely.

Also, as to your suggestions for the magic level of those involved and respectives ages, I'm fine with all that. Sounds brilliant, actually. Now, there's no reason the two non-magic-users have to be capable (even on a low-medium level) but since your average person can do some magic it's likely that they'll have one or two spells, even if they're not much alongside the witch and mage.

One more important thing - did the post length bother you? I know the first post is going to be kinda long, so I can insert more intentional paragraph breaks if that'd make it easier on you. Please don't hesitate to ask if you need something.